The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 18, 1992
Filed:
Nov. 15, 1990
Applicant:
Inventors:
Craig M Davis, Puyallup, WA (US);
Richard R Rasmussen, Fremont, CA (US);
Assignee:
National Semiconductor Corporation, Santa Clara, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03K / ; H03K / ;
U.S. Cl.
CPC ...
307451 ; 307455 ; 307475 ; 307354 ; 307242 ;
Abstract
The present invention provides a CMOS output buffer with ECL output characteristics that allows the outputs to be terminated in any manner desired and which is not limited by the op amp settling time. The buffer establishes a bus internally for the VOH and VOL levels and then switches between the buses using transmission gates. In the disclosed embodiment of the invention, the op amp's feedback path includes a P-channel device which is either identical to or, to conserve power, a carefully scaled down equivalent of the P-channel output device.